Brake structure



May 13, 1952 c. HOLLERITH 2,596,556

BRAKE STRUCTURE Filed July 10, 1946 4 Sheets-Sheet l CHEN-1E5 HULLEFITHy 13, 1952 c. HOLLERITH 2,596,556

BRAKE STRUCTURE ijg- E- I 4 EHIIIF'LEE HULLEFP/ TH 9% fi mffbu y 13,1952 c. HOLLERITH 2,596,556

BRAKE STRUCTURE Filed July 10, 1946 4 Sheets-Sheet 3 EHHF'L E5 HULLEFITH3% flmnm a- 2M M y 1952 c. HOLLERITH 2,596,556

BRAKE STRUCTURE Filed July 10, 1946 4 Sheets-Sheet 4 1... specificationand the concluding claims.

Patented May 13, 1952 UNITED stares-*- PATENT -qsorrwe BRAKE STRUGTURECharles Hollerith, Jackson; Mich.,-assignor, by mesne assignments, toThe B. F. Goodrich Company, Akron,10hio, a corporation f..New

I York Application July 10, 1946, Serial No. 682,671

4 Claims.

" ..The. present inventionrelates to improvements in discbrakes.

An robject of the invention is to provide an improved disc brake of thetype in whicha radial H disc is rotated between brake. elements imposedupon only' a fractional portion of the braking surface of thedisc; withthe remaining portion exposed for radiation.

Another object is to provide an improved brake of the type described inthe previous paragraphin. which the brake elements onopposite sides ofthe discs are in theiormof relatively small circular blocks to provide,circumferentially spaced localized areas of high unit pressure betweenwhich the rotating disc is. floated.

Fig. 4 is a cross sectional view through the distributor valve on theline IVIV of Figure l 2, and

Fig. 5 is a fragmentary sectional. view taken on line VV of Fig. 3.

Referring to: the drawings, and particularly to Fig. 1', the principlesof the invention have 7 been illustrated in connection-with an aircraftwheel ID of cast construction supported upon suitable bearings l2 and I4for rotation upon the fixed. axle l5 equipped witha flange 18. towhich..the.brake structuregenei'ally designatedby reference character 26 isattached by bolts 22.

. Torquemembersi i are. fixedly attached to the v Afurther object of theinvention is to provide .a radial disc type brake in which improvedservo-action has been devised.

A still further object is to provide an improved hydraulic servo-brakeof the type described in the first-stated object in which theactuatingpressure for the opposed brake elements is developed by displacement ofa movable wall of a closed systemthrough a .f rictional coupling withthe radial disc.

Another object is-to provideanimprcved hydraulic brake system in theform of a closed system intimately associatedwith .a wheel struc- "tureand actuated by-servo-action.

V Afurther object is to provide hydraulic tirely contained at the wheeland having a servomechanical coupling" with a rotatingpart of the I--vvheel.

A still further object of the inventio n resides in the novelarrangement'fordeveloping linear swheel Ill bysscrews 25. The.radialdisc 28 has .a; tongue and grooveconnection with the torquemembers, 24 so, that. it is driven thereby as a unit with thewwheel l5.Thedisc 28,.however,

. tis capable'offioating.aetion in1an axialdirection as. will be m0refully. described.

Settle-mechanism As more clearly shown inFigs; 1 and 3, theservooperating mechanism for developing the responding shape.

brake applying hydraulic pressure comprises a rigid cast part 30 havinga cylindrical recess 32 in which is supported a brake block 34 of cor-As an integralwpart of the member 30, a collar; 36 is providedwhich issupbrake system in the form of a closed system enport-ed for slightrelative rotational m ovement upon the bearing. :sleeve 38 which is inturn mountedupon the flange sleeve 40 attached to the torque fiangeJl2by screws 44; The torque .,tlange of thebrake-Zil is in turn fastened tothe movements in a hydraulic cylinder throu gh a frictional couplingWith-a rotated source of energy.

These and other objectsand advantages residing in the details ofconstruction, arrangement and combinationof" parts will merc fully I-appear.. and beappreciated by those skilled in r the art. from aconsideration oi the following In thedrawings,

Fig. 1 is a vertical cross-secticnalview through an aircraft wheelembodying the principles of the present invention and takenon .line I-Iof Fig. 2, Fig; 2 is an elevational viewof thebrakestructure viewed fromthe insideand tetheright as shownin Fig. 1, r

Fi 3;is.;an.outside view or: the: brakeetructure .ithzthawheel removed,

flange- [8 oftheaxle' I6 by bolts 22.

Secured to the mernber 36 by tie bolts; 45 is a casting 48 which extendsacross theinside of the brake. disc 28 and then'radiallyf outwardlyThreadably secured and axially adjustable in the head 56 is anadjustment nut 69 having a central chamber 62 to receive a spring 64which .gacts against.theheadwficcf the bolt. 5.! to re- 5132685013 the.piston 52.. .and its associated brake block 54; By screwing the nut inor out the clearance between the 'disc -28 and the, brake block yliglmaylbe; adjustedibs chamber in 'hich hydraulicrpressure is directed toactuate the-pistonr-fsziii-thepylindr' fielis indicated by referencecharacter it. As more clearly shown in Fig. 2 the chamber II) is incommunication with the fitting I2 which is in turn connected by aflexible hose line it to the servo distributor valve I6 more fully shownin Fig. 4. Movement of the member 353 and its associated parts isdetermined by the clearance between the shoulders I8 and the stops 89upon the main body portion SI of the brake 20.

It will be readily understood that when hydraulic stress is directedinto the chamber I8 that the spring 64 will be pressed and the brakedisc 28 will be clamped between the brake blocks 34 and 56. This actionsets up a frictional drag tending to cause the member 30 to rotate withthe disc 23 resulting in a partial rotation of the member 39 eitherclockwise or counterclockwise, depending upon direction of rotation ofthe wheel ID. Such partial rotation has its maximum limits defined bythe point of engagement between the shoulders l8 and stops at.

The mechanism for transforming partial rotation of the member 33 intolinear movement capable of moving a servo piston 82 is more clearlyshown in Fig. 3 and comprises a yoke-shaped member 812 having arcuatearms 65 and 3 with the ends thereof forked at 99 to engage with pins SIattached to the member 3t. Tension springs 92 connected at 94 at theirupper end to the yoke member 86 are connected at their lower end at atto the brake ZII. It will be noted that the pins Eli are slightly belowthe center of rotation.

The yoke member 84 has a central stem 93 in which is adjustably threadeda stud IIII) locked in positions of adjustment by the lock nut I82. Atits upper end stud IBI] has a ball portion I M which fits into acorresponding socket I06 in the piston 82. The piston 82 is heldassembled to the stud IEO through a spring washer I08 held in positionby a snap ring III Casting II2 has a cylindrical bore I I I in which asleeve I I6 is pressfitted to provide a cylinder for the piston 82 tooperate. The chamber in which hydraulic pressure is developed bymovement of the piston 82 is indicated by reference character I It. Ableeder hole is indicated at I20 for bleeding any air from the pistonand this hole is sealed by a suitable screw I22 acting against a sealingwasher I24. The member I I2, preferably a casting reinforced by suitablewebs I26, is illustrated as having three cylindrical recesses I23 inwhich are supported similarly shaped brake blocks I30. I A plurality ofstuds I3I are threaded into a member II2 to receive nuts I33 to firmlysecure member I I2 and the main body iii to the brake 29.

With the member II2 fixedly attached to the fixed brake 20, and the ballmember I04 of the stud I90 held within the socket I06, counterclockwiserotation of the member 39 as Viewed in Fig. 3 will result in therighthand pin 9I lifting the yoke 85 against the tension of thecorresponding spring 92. Such upward movement of the yoke 84 will resultin similar movement being imparted to the piston 82 to build up apressure in the chamber I I8.

Disc mechanism portion of each torque member 2a projects into the slotsI35 of the radial brake disc 23 as more -clearly shown in Figs-2 and 3.It is to be under.-

4 stood that the members 25 have a sliding fit in the slots I36 topermit the disc 28 to have a floating movement in an axial directionbetween the brake blocks 3 and 54 as well as between the brake blocksI30 and I38.

Brake mechanism The principal braking action upon the disc 23 to controlrotation of the wheel I8 is performed by the clamping action of the disc23 between brake blocks I38 and I38. The brake blocks I38 are attachedto the pistons ltd which in the illustrated form of the invention arethree in number and may correspond in structure to the pistons 52. Thecylinders I42 in which the pistons I tii operate has a head I415 held inposition by studs I45. The adjustment nut M8 is threaded in the head Mdand is recessed at IEE to receive the spring I52 acting against the headI555 of the shank I55 connected with piston its. The nut I48 is adjustedin the head I I I to control the clearance between the brake blocks I33,I38 and the disc 28. The hydraulic pressure developed in the chamber H8is in communication with the chambers I53 of the cylinders hi2 so as tomove the piston E43 and their associated brake blocks I38 toward thedisc 23. The hydraulic circuit will be described hereinafter.

H ydmulic circuit In service, the brake structure will be mounted withthe line II of Fig. 2 horizontally disposed. This will dispose thebleeder port IEiI at the top so that any air may be removed from thesystem at the time it is filled With hydraulic fluid. The valve 15 isconnected with the usual pedal master cylinder at the inlet I82 (seeFig. 4) through a suitable conduit not shown. When the pedal is intiallyactuated, the piston I 64 is in the position shown. Upon initial flow offluid pressure, the piston I64 is moved to the right as viewed in Fig. 4to close the port I68 communicating with chambers I58 through thepassage Hi. There after, the entire flow of fluid pressure is throughthe line I4 to the chamber 78.

Displacement of the piston 52 by fluid pressure in the chamber 10results in the displacement of the piston 82 in the chamber H8 throughthe chain of mechanism heretofore described. The fluid pressuredeveloped in the chamber II 8 leaves the chamber II3 through transversepassages I70, and is delivered to the outside chambers I58 throughpassages I1 2, I'M and I16. The central chamber I58 is supplied throughpassages IIB communicating with the outside chambers I58. As shown inFig. 5, each passage I14 has a joint between the body 8| and the memberII2 sealed by an insert I85! having sealing rings engaging withcounterbores located on each side of the joint.

The feel of brake application is carried back to the foot pedal by thepressure developed-in chambers I58 being fed back through the connectionI10 and the port I68 against the piston valve I64, as will readily beunderstood. As only a running clearance is required between the disc 28and the block 54, a very small amount of fluid need be delivered to thechamber It to effect a much greater displacement of fluid in the chamberIIB. This arrangement materially reduces the time lag between pedalactuation and brake application.

In the appended claims, the pistons 52, S2, and I40 are referred to asdisplaceable walls in order to bring within the scope of the presentinvention the diaphragm and other equivalent structure for accomplishingthe same result.

Having thus described my invention, what I claim as new and desire tocover by Letters Patent is:

1. A servo-type wheel brake structure comprising in combination with arotatable wheel body part and shaft mounting therefor, a radial brakedisc extending between said shaft and wheel body, axially extending pinand slot connection means between said brake disc and said wheel bodyfor rotation by the latter, while enabling axial floating movement ofthe brake disc relative to said wheel to take place, a brake structureon said shaft, said brake structure including opposed brake pads onopposite sides of said brake disc and in circumferentially adjacentassembly thereto, hydraulic pressure fluid displacement meansoperatively associated with said brake pads to efiect braking engagementof the latter with said disc, conduit means for connection to a remotesource of brake applying hydraulic pressure to initiate the brakeapplication, a servo-mechanism for augmenting the brake applyinghydraulic pressure, said servo-mechanism comprising an actuatorstructure rotatably mounted about said shaft for limited oscillatorymotion in opposite directions, a hydraulic pressure actuated rotationretarding means for said disc and carried by said actuator structure indiametral relation to said brake pad assembly, a hydraulic chamber onsaid brake structure, a fluid displacement wall in said chamber, anoperating member for said wall, means connecting said operating memberwith said actuator structure to effect movement of said wall byoscillation of the said actuator structure in either direction, andhydraulic connections between said rotation retarding means,servo-chamber and hydraulic pressure fluid displacement means adapted toeffect operation of the latter to apply the braking pressure under thecontrol of said servo-mechanism.

2. The invention as defined in claim 1, said means connecting saidoperating member with said actuator structure comprising a yoke membercentrally connected with the displacement wall of said servo chamber,and means connecting opposite ends of said yoke member with saidoscillatory actuating structure to convert partial rotary movement ofthe latter in either direction into linear movement of said displacementwall of said servo-chamber.

3. A servo-type radial disc wheel brake comprising in combination with awheel, a radial brake disc of annular shape rotatable with the wheel,brake means located on one side of said disc and selectively engageabletherewith, a displaceable wall located upon the same side of said discas said brake means and operatively connected to said brake means, asecond displaceable wall located upon the opposite side of said discfrom said first wall, relatively fixed wall structure associated withsaid walls to define chambers, conduit means defined by structureconnecting said chambers and extending between opposite sides of saiddisc across the inner peripheral edge thereof, servo means including anoscillatable actuator structure disposed upon said opposite side of saiddisc, a friction member selectively engageable with said disc, means formoving said friction member into engagement with said disc, meanssupporting said member on said first side of said disc, said membersupporting means being carried by said actuator structure across theinner peripheral edge of said disc, engagement between said frictionmember and said disc reacting through said supporting means to impartpartial rotation to said actuator structure in one direction or theother depending upon the direction of rotation of said wheel, meansengaged and operated by the oscillation of said actuator in eitherdirection and operatively connected to said second displaceable wall todisplace fluid from one of said chambers into the other to displace saidfirst wall to actuate said brake means into braking engagement with saiddisc.

4. A servo-type radial disc wheel brake having a substantiallyself-contained hydraulic actuating system comprising a radial rotatabledisc of annular shape, a fixed mounting structure, a brake partselectively engageable with and supported on one side of said disc, adisplaceable wall operatively connected to said brake part and disposedon the same side of said disc, a second displaceable wall supported insaid fixed structure on the opposite side of said disc, wall structuredefining first and second chambers associated with said first and secondwalls, respectively, hydraulic connection structure extending betweensaid first and second chambers and across the inner-peripheral edge ofsaid disc, an oscillatable actuator carried in said mounting structureand disposed on the side of said disc opposite from said brake part,friction means engageable with said disc to energize said actuator tooscillate the same in one direction or the other depending upon thedirection of rotation of said disc, said friction means including adisplaceable wall, wall structure associated with said last wall anddefining a third chamber, a hydraulic connection between said thirdchamber and said first and second chambers, means engaged and operatedby the oscillation of said actuator in either direction and operativelyconnected to said second displaceable wall to displace fluid from one ofsaid first and second chambers into the other to displace said firstwall to actuate said brake part into braking engagement with said disc,and a hydraulic connection between said third chamber and a source offluid pressure to initiate the servo-action.

CHARLES HOLLERITH.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

